Analysis of the electric field gradient in the perovskites SrTiO3 and BaTiO3: density functional and model calculations

We analyze recent measurements [R. Blinc, V. V. Laguta, B. Zalar, M. Itoh and H. Krakauer, J. Phys. : Cond. Mat., v.20, 085204 (2008)] of the electric field gradient on the oxygen site in the perovskites SrTiO3 and BaTiO3, which revealed, in agreement with calculations, a large difference in the EFG for these two compounds. In order to analyze the origin of this difference, we have performed density functional electronic structure calculations within the local-orbital scheme FPLO. Our analysis yields the counter-intuitive behavior that the EFG increases upon lattice expansion. Applying the standard model for perovskites, the effective two-level p-d Hamiltonian, can not explain the observed behavior. In order to describe the EFG dependence correctly, a model beyond this usually sufficient p-d Hamiltonian is needed. We demonstrate that the counter-intuitive increase of the EFG upon lattice expansion can be explained by a s-p-d model, containing the contribution of the oxygen 2s states to the crystal field on the Ti site. The proposed model extension is of general relevance for all related transition metal oxides with similar crystal structure.Comment: 10 pages, 4 figure

The methods of students training of chelyabinsk energy college for contests and competitions

В статье приводится обобщение опыта подготовки квалифицированных специалистов в области энергетики в Челябинском энергетическом колледже. Ведущая роль отводится производственному обучению, в ходе которого формируются основные общие и профессиональные компетенции, а также к участию в конкурсах профмастерства, в том числе по стандартам WorldSkills.This article deals with a summarizing of the experiment of qualified specialists training in the sphere of energy. The experiment was conducted at “Chelyabinsk Energy College”. The main part is assigned to the industrial training, in the course of which the basic general and professional competences, and also desire for participation in professional skills competitions are formed at students. Special attention is dedicated to the question of training for the competitions on WorldSkills standards

Cytokine profile in hospitalized patients with COVID-19 of different severity

Analysis of cytokine profile markers in conjunction with the clinical manifestations of coronavirus disease 2019 (COVID-19) can provide valuable information about the pathogenetic manifestations of the disease, and therefore, in the future, determine drugs that affect the cytokine storm and have an anti-inflammatory effect.Aim. To identify correlations between the parameters of the developed cytokine profile and the clinical course in hospitalized patients with COVID-19 of different severity.Material and methods. The study included 70 hospitalized patients with a confirmed diagnosis of COVID-19, with a mean age of 58 [50;69] years, including 40 men (57%) and 30 women (43%). The average lung involvement according to computed tomography (CT) at admission was CT-2 [1;3]. Peripheral venous blood was taken at admission, which averaged 7 [6; 8] days from the symptom onset. Standard biochemical parameters were studied, as well as 47 cytokines and chemokines using the Multiplex system (Merck KGaA, Darmstadt, Germany).Results. Correlations was found between the lung involvement degree and the level of IL-8 (r=0,31, p<0,05), IL-15 (r=0,35, p<0,05), IL-18 (r=0,31, p<0,05), MCP-1 (r=0,36, p<0,05), MIG (r=0,50, p<0,05), TNF-α (r=0,41, p<0,05). An inverse correlation was also found in the level of blood oxygen saturation with the same indicators as follows: IL-8 (r=-0,27, p<0,05), IL-15 (r=-0,34, p<0,05), IL-18 (r=-0,31, p<0,05), MCP-1 (r=-0,40, p<0,05), MIG (r=-0,56, p<0,05), TNF-α (r=-0,45, p<0,05). IL-6 levels were significantly elevated in patients with severe COVID-19 (CT3, CT4), while no increase in IL-6 was observed in patients with moderate disease (CT1, CT2). It is noteworthy that in patients with diabetes, the highest values of IL-12, IL-9 were recorded.Conclusion. Hyperinflammatory syndrome in severe COVID-19 is manifested by high levels of IL-6, MIG, MDC, MCP-1, M-CSF, TNF-α, β, IL-8, IL-18, IL-15. With the CT-1 and CT-2, an increase in only the level of IL-18, IL-8 is noted. The identified patterns prove and make it possible to explain a number of systemic inflammatory changes that occur with COVID-19

Роль убиквитин-протеасомной системы в развитии плоскоклеточного рака полости рта

 The ubiquitin-proteasome system (UPS) controls the activity, subcellular localization, and stability of many cellular proteins that affect cellular homeostasis by regulating multiple signaling cascades. The activity of this system is associated with the emergence and progression of oral squamous cell carcinoma, since specific proteolysis of most intracellular proteins involved in the pathogenesis of cancer is implemented by this system.The review article presents data on the characteristics of proteasomes and the process of substrate protein ubiquitination. The role of the ubiquitin-proteasome system in the pathogenesis of oral squamous cell carcinoma is shown, and the prospects of its use in precancerous diseases are described. The  literature search was carried out in the search engines Medline, eLIBRARY, Scopus, The Cochrane Library, and RSCI.  Убиквитин-протеасомная система контролирует активность, субклеточную локализацию и стабильность множества клеточных белков, которые влияют на клеточный гомеостаз посредством регуляции сигнальных каскадов. Активность данной системы связана с возникновением и  прогрессированием плоскоклеточного рака полости рта, так как специфический протеолиз большинства  внутриклеточных протеинов, участвующих в патогенезе рака, происходит с помощью вышеупомянутой системы.В обзорной статье представлены данные о характеристике  протеасом и процессе убиквинтирования белковсубстратов. Показана роль убиквитин-протеасомной системы в  патогенезе плоскоклеточного рака полости рта, приведены сведения о перспективах использования ее при предраке. Поиск литературы осуществлялся в поисковых системах Medline, Elibrary, Scopus, The Cochrane Library, РИНЦ.

Экспрессия мРНК кальпаинов и их активность в злокачественном и диспластически измененном эпителии верхних дыхательных путей

 Background. The calpain proteolytic system plays an important role in the development of cancer. Detection of early cancer in the upper respiratory tract is often challenging, as symptoms are largely non-specific, and most cases are diagnosed at an advanced stage.Aim. To identify candidate markers of transition from premalignant lesions to invasive carcinoma, we studied mRNA expression levels of CAPN1 and CAPN2 and the total activity of calpains in the tumor tissues of patients with head and neck squamous cell carcinoma (HNSCC) and in the epithelial dysplasia-affected tissues of patients with chronic diseases of the upper respiratory tract.Materials and methods. The study included 32 patients with HNSCC (Т1-3N0-1М0) and 12 patients with chronic diseases of the upper respiratory system associated with epithelial dysplasia. The expression levels of CAPN1 and CAPN2 were assessed using real-time polymerase chain reaction (PCR). The calpain activity was determined by hydrolysis of the fluorogenic Suc-LLVY-AMC oligopeptide.Results. The mRNA expression levels of CAPN1 and CAPN2 were respectively 3 and 4 times higher in the tumor tissue of patients with HNSCC than in the tissue of patients with endothelial dysplasia in the upper respiratory tract. The level of calpain activity was 4.4 times higher in patients with HNSCC than in patients with epithelial dysplasia of different severity.Conclusion. The elevated mRNA expression levels of CAPN1 and CAPN2 and their activity in the tumor tissues of patients with HNSCC compared to patients with chronic respiratory diseases associated with epithelial dysplasia are likely to characterize a high potential for transition from precancerous lesion to cancer. To clarify the role of calpains in the carcinogenesis of HNSCC, further studies of intact tissues using animal models are required.   Актуальность. Кальпаиновая протеолитическая система играет важную роль в развитии злокачественных опухолей. В настоящее время диагностика рака верхних дыхательных путей на ранних стадиях проводится редко, заболевание часто характеризуется запущенностью опухолевого  процесса.С целью поиска кандидатных маркеров перехода  предопухолевых заболеваний в злокачественные изучали уровни экспрессии мРНК CAPN1, CAPN2 и общей активности  кальпаинов в опухолевой ткани пациентов с плоскоклеточным раком головы и шеи (ПРГШ) и в  диспластически измененном эпителии верхних дыхательных путей.Материалы и методы. В исследование были включены 32 пациента с ПРГШ (Т1-3N0-1М0), группу больных с предопухолевой патологией составили 12 пациентов с  хроническими заболеваниями верхних отделов дыхательной системы, ассоциированными с  диспластическими изменениями эпителия различной  степени. Уровень экспрессии мРНК CAPN1 и CAPN2 оценивался с помощью полимеразной цепной реакции в  режиме реального времени. Активность кальпаинов  определяли по гидролизу флуорогенного олигопептида Suc-LLVY-AMC.Результаты. Показано увеличение уровня экспрессии мРНК CAPN1 и CAPN2 (в 3 и 4 раза соответственно) в опухолевой ткани у пациентов с ПРГШ в сравнении с диспластически  измененным эпителием верхних дыхательных путей. Также отмечен высокий уровень активности кальпаинов у больных  ПРГШ, который в 4,4 раза превышал показатели, полученные для пациентов с диспластическими  изменениями эпителия различной степени.Заключение. Вероятно, увеличение уровня мРНК CAPN1 и  CAPN2 и общей активности кальпаинов в опухолевых тканях  пациентов с ПРГШ в сравнении с пациентами с  хроническими заболеваниями, ассоциированными с  диспластическими изменениями различной степени, может  играть важную роль в процессе перехода предрака в рак. Для полного установления роли кальпаинов в  канцерогенезе ПРГШ необходимо дальнейшее проведение подобных исследований в интактной ткани, что возможно  только на экспериментальных моделях.

Functional characterization and biological significance of Yersinia pestis lipopolysaccharide biosynthesis genes

The Gram negative bacterium Yersinia pestis is the etiological agent of flea transmitted fulminant systemic rodent zoonosis and the reason of the three devastating pandemics of plague Lipopolysaccharide (LPS, endotoxin) is an impor tant factor of pathogenicity of Gram negative bacteria. The full LPS molecule (S form LPS) consists of three well defined domains: i) lipid A composed of sugars, fatty acids, and phosphate; it represents the endotoxic princi ple of the LPS and anchors it in the outer membrane; ii) a core oligosaccharide containing charged groups; and iii) an O specific polysaccharide (O antigen), which carries ISSN 0006 2979, Biochemistry (Moscow), 2011, Vol. 76, No. 7, pp. 808 822. © Pleiades Publishing, Ltd., 2011. Published in Russian in Biokhimiya, 2011, Vol. 76, No. 7, pp. 989 1005 Abstract-In silico analysis of available bacterial genomes revealed the phylogenetic proximity levels of enzymes responsible for biosynthesis of lipopolysaccharide (LPS) of Yersinia pestis, the cause of plague, to homologous proteins of closely relat ed Yersinia spp. and some other bacteria (Serratia proteamaculans, Erwinia carotovora, Burkholderia dolosa, Photorhabdus luminescens and others). Isogenic Y. pestis mutants with single or double mutations in 14 genes of LPS biosynthetic path ways were constructed by site directed mutagenesis on the base of the virulent strain 231 and its attenuated derivative. Using high resolution electrospray ionization mass spectrometry, the full LPS structures were elucidated in each mutant, and the sequence of monosaccharide transfers in the assembly of the LPS core was inferred. Truncation of the core decreased sig nificantly the resistance of bacteria to normal human serum and polymyxin B, the latter probably as a result of a less effi cient incorporation of 4 amino 4 deoxyarabinose into lipid A. Impairing of LPS biosynthesis resulted also in reduction of LPS dependent enzymatic activities of plasminogen activator and elevation of LD 50 and average survival time in mice and guinea pigs infected with experimental plague. Unraveling correlations between biological properties of bacteria and partic ular LPS structures may help a better understanding of pathogenesis of plague and implication of appropriate genes as potential molecular targets for treatment of plague